Acyclovir

25 interactions 535 cited references
Also sold as: Avaclyr Sitavig Sitavig® Zovirax Zovirax® Capsules Zovirax® Tablets
About Acyclovir

Acyclovir is an antiviral medication used to treat chickenpox, shingles, and genital herpes infections. Read the full Acyclovir drug information page →

Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated Jul 11, 2026 · Editorial policy · Data sources

Sources: FDA prescribing information (Structured Product Labeling), the published literature cited in each entry, DDInter 2.0 (a major open-access drug-interaction database), and legacy DrugBank interaction data distributed by the NIH's RxNav service (decommissioned in 2024) — analyzed and reviewed by our pharmacist team. How we build this library →

Most serious with: Fezolinetant Bupropion Clomipramine Dichlorphenamide Emtricitabine Fexinidazole
1 Contraindicated 18 Major 5 Moderate 1 Minor
All (25) Contraindicated (1) Major (18) Moderate (5) Minor (1)

Contraindicated

Acyclovir Fezolinetant Increased fezolinetant exposure Details

Major

Acyclovir Bupropion Aplenzin Increased risk of seizures Details Acyclovir Clomipramine Anafranil Increased clomiPRAMINE exposure and an increased risk of seizures Details Acyclovir Dichlorphenamide Increased OAT1 substrate exposure Details Acyclovir Emtricitabine Emtriva Increased emtricitabine exposure and an increased risk of emtricitabine-related adverse effects Details Acyclovir Fexinidazole Increased exposure of OAT1/OAT3 substrate Details Acyclovir Foscarnet Foscavir Nephrotoxicity Details Acyclovir Hydroxychloroquine Plaquenil An increased risk of seizures Details Acyclovir Leflunomide Arava Increased exposure of OAT3 substrate Details Acyclovir Mycophenolate Mofetil Increased acyclovir exposure and an increased risk of acyclovir-related adverse reactions Details Acyclovir Nitisinone Increased OAT1 or OAT3 substrate exposure and an increased risk of OAT1 or OAT3 substrate-related adverse effects Details Acyclovir Pimozide Increased pimozide exposure and an increased risk of pimozide-related adverse reactions Details Acyclovir Tenofovir Alafenamide Increased tenofovir alafenamide exposure and an increased risk of tenofovir alafenamide-related adverse effects Details Acyclovir Teriflunomide Aubagio Increased exposure of OAT3 substrate Details Acyclovir Tizanidine Increased tiZANidine exposure and an increased risk of tiZANidine-related hypotension, bradycardia or increased drowsiness Details Acyclovir Tramadol ConZip An increased risk of seizure Details Acyclovir Vadadustat Vafseo Increased OAT3 substrate exposure and an increased risk of OAT3 substrate-related adverse effect Details Acyclovir Warfarin Coumadin Increased warfarin exposure and an increased INR Details Acyclovir Foscarnet Injection Foscavir Nephrotoxicity Details

Moderate

Acyclovir Fosphenytoin Cerebyx Decreased phenytoin plasma concentrations and potential increased seizure activity Details Acyclovir Meperidine Demerol Increased meperidine and its metabolite normeperidine exposure Details Acyclovir Phenytoin Dilantin Decreased phenytoin plasma concentrations and potential increased seizure activity Details Acyclovir Probenecid Increased OAT3 substrate exposure Details Acyclovir Valproic Acid Depakene® Decreased valproic acid plasma concentrations and potential increased seizure activity Details

Minor

Acyclovir Zidovudine Retrovir Increased lethargy and fatigue Details

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Educational information only, not medical advice. Always confirm interactions with your pharmacist or prescriber before making any change to your medications.